<!DOCTYPE html>
<html lang="zh">
<head>
  <meta charset="UTF-8">
  <title>{% block title %}{% endblock %}</title>
  <!--    引用bootstrap css js ,jquery -->
  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">

  <script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.js"></script>
 <script src="https://cdn.jsdelivr.net/npm/bootstrap@3.3.7/dist/js/bootstrap.min.js" integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa" crossorigin="anonymous"></script>
</head >
<body>
{% block content %}
{% endblock %}
</body>
</html>